Now showing 1 - 10 of 20
  • Publication
    Parametric investigation on different bone densities to avoid thermal necrosis during bone drilling process
    ( 2021-10-25)
    Islam M.A.
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    Suhaimi M.F.F.
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    Mat F.
    Bone drilling is a universal surgical procedure commonly used for internal fracture fixation, implant placement, or reconstructive surgery in orthopedics and dentistry. The increased temperature during such treatment increases the risk of thermal penetration of the bone, which may delay healing or compromise the fixation's integrity. Thus, avoiding penetration during bone drilling is critical to ensuring the implant's stability, which needs surgical drills with an optimized design. Bovine femur and mandible bones are chosen as the work material since human bones are not available, and they are the closest animal bone to human bone in terms of properties. In the present study, the Taguchi fractional factorial approach was used to determine the best design of surgical drills by comparing the drilling properties (i.e., signal-to-noise ratio and temperature rise). The control factors (spindle speed, drill bit diameter, drill site depth, and their levels) were arranged in an L9 orthogonal array. Drilling experiments were done using nine experimental drills with three repetitions. The findings of this study indicate that the ideal values of the surgical drill's three parameters combination (S1D1Di2) and their percentage contribution are dependent on the drilling levels of the parameters. However, the result shows that the spindle speed has the highest temperature effect among other parameters in both (femur and mandible) bones.
  • Publication
    Thermal Management System Analysis Concentrate on Air Forced Cooling for Small Space Compartment and Heat Load
    ( 2021-12-01)
    Yahaya M.N.
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    Ghani A.Z.A.
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    Rahman A.A.
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    Bakar S.A.
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    Harun A.
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    Hashim M.S.M.
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    Kamarrudin N.S.
    Battery thermal management system (BTMS) plays an important thing as to control of the battery thermal behaviours. Recently, most of the manufacturer either in automobile, motorcycle, and electric vehicle (EV) industry are using this application of BTMS for their product. It is because BTMS promising the extend the period and lifespan of the battery and the battery system controlling the temperature distribution and circulation on the system. Lithium-ion battery is one of the common usages in BTMS. Lithium-ion battery promising the goals such as higher performance, better cycle stability, and improved protection are being followed with the selection and engineering of acceptable electrode materials. It also shows a goal for future such as high of the energy storage due to higher energy density by weight among other rechargeable batteries. However, there still have factor that are limiting the performance/application when using lithium-ion as battery thermal management system (BTMS). For example, the performance, cost, life, and protection of the battery. The main reason is therefore important in order to achieve optimum efficiency whenworking under different conditions. Hence, the best range of temperature and the cooling capacity of lithium-ion battery need to evaluate in order to increasing the lifespan of lithium-ion battery at the same time can increasing the performance of the cell. This study found that the higher the velocity of air, the higher the cooling capacity that gain from the surrounding. It also was strongly related to the dry bulb temperature of surrounding air.
  • Publication
    Determination of effective elastic properties of metal matrix composites with damage particulates using homogenization method
    The present study aims to investigate the effect of micro-damage in particulates metal matrix composite on the elastic properties. The micro damage that perhaps could occurs during manufacturing process or due to environmental effects was modelled in three different types, namely shattered, debonded and breakage particulates with variation of volume fraction. The modelling and analysis were conducted based on homogenization theory by utilizing multiscale finite element software (Voxelxon). The results suggest that the elastic properties of metal matrix composite was sensitive to the geometrical defects of its particle.
  • Publication
    Quantifying the Impact of Drilling Parameters on Temperature Elevation within Bone during the Process of Implant Site Preparation
    ( 2024-04-01)
    Islam M.A.
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    Kamarrudin N.S.
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    Noor S.N.F.M.
    This study aimed to elucidate the influences of several drilling parameters on bone temperature during drilling, as excessive heat generation can cause thermal bone damage and affect post-surgery recovery. In vitro drilling tests were conducted on bovine femoral shaft cortical bone specimens. The parameters considered included tool rotational speed (s), feed rate (f), tool diameter (d), and drill tip angles of 118° and 135°. Drilling temperatures were studied across a range of 800–2000 rpm rotational speeds, 20–40 mm/min feed rates, and 2–4 mm drill diameters. A predictive statistical model was constructed using the response surface methodology (RSM). Analysis of variance (ANOVA) at a 95% confidence level (α = 0.05) revealed that rotational speed significantly impacted temperature increase, contributing to 59.74% of observed temperature rises. Drill diameter accounted for 16.21% of temperature variations, while feed rate contributed to 10.04% of the temperature rises. The study provides valuable insights into the predominant factors affecting bone temperature during drilling. Understanding these parameters and their interplay is pivotal for optimizing drilling conditions and minimizing potential thermal damage to bones.
  • Publication
    Engine performance enhancement by improving heat transfer in between exhaust valve and valve seat through CFD (transient thermal) simulation
    ( 2021-05-03)
    Mohamad Aniq Syazwan Mohamed Hassan
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    Aziz I.A.
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    Ibrahim Z.
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    Muhammad Faiz Hilmi Rani
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    Rishan Murali
    The combustion of the internal combustion engine results in high heat and pressure produce as exhaust gas. The high-temperature exhaust gas will transfer the heat to surrounding via convection, conduction, and radiation. In the combustion chamber, the exhaust valve and its seat will reach high temperatures due to hot gases exit through the engine exhaust port. This high temperature must be reduced to avoid damaging the engine. In this project, the existing material of the valve seat is tested using computational fluid dynamics simulation for heat analysis. Simulation of transient thermal is conducted to study the detailed behavior of heat transfer of the valve and valve seat in the engine. Four copper-based material of the valve seat is selected which is beryllium copper, chromium copper, brass, bronze are simulated. In the simulation, the brass valve seat has the highest heat absorbance rate which averagely 30% higher than cast iron valve seat in terms of temperature differences. Most of the copper-based valve seat can absorb averagely 10% to 30% more heat than cast iron valve seat depends on the material's thermal conductivity.
      3  17
  • Publication
    Homogenized properties of porous microstructure: effect of void shape and arrangement
    This paper aims to investigate the effect of void shape and arrangement on the effective elastic properties of porous microstructure. The characteristics of the voids are in different shapes, sizes and arrangement. The porous microstructure models were developed using CATIA. Then, Voxelcon was employed to analyse the multiscale finite element model and determine the homogenized properties. Based on the results, void shape, size, and arrangement of porous microstructure were found sensitive to the elastic (homogenized) properties. Ellipsoidal shape having the highest Young's modulus, whereas the spherical shape has the highest Poisson's ratio and shear modulus. Cubical shape was the lowest for all the elastic properties. Moreover, the formation arrangement in void cubical shape produced the highest Young's modulus and shear modulus.
      2  19
  • Publication
    Engine Performance Analysis by Studying Heat Transfer in the Valve Seat through Steady-State Thermal Simulation
    As the engine reached high speed, the exhaust valve temperature increased exponentially due to the exhaust gas produced by the combustion process between the mixture of air and fuel within the combustion chamber of the internal combustion engine. The valve is subjected to thermal loading due to high temperature and pressure within the cylinder, which must withstand a material temperature for sustainable and optimal operation. To avoid this loss, a perfect medium must be prepared to ensure that the heat is extracted smoothly. This can be done when the valve is in contact with the seat and there is a periodic heat transfer contact. Therefore, it is imperative to research the correlation between valve and valve seat to understand the two sections' heat transfer mechanism. In this study, thermal contact analysis was used to identify heat transfer between the valve and the valve seat as both parts are interconnected. This research also has an interest in studying the two surface conduction mechanisms as the exhaust valve closed in steady-state conditions. Thus, this study portrays a significant method, particularly for the determining the distribution of temperature, heat flux, and heat flux direction between the valve and its seat using ANSYS Workbench.
      2
  • Publication
    Numerical evaluation of aluminium 6026-T9 fracture toughness
    ( 2021-10-25)
    Zulkifli A.N.
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    Hashim M.S.M.
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    Ismail A.H.
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    Fracture is the separation of an object into two or more pieces caused by crack growth under the action of applied stress. There are many different methods for fracture evaluation has been made but still lacks information on properties of Aluminium 6026-T9. Aluminium 6026 is non-toxic since it does not contain Tin (Sn) and features a great corrosion resistance. This study focuses on the mechanical properties and fracture toughness of Aluminium 6026-T9. The material is cut and shaped into dog-bone specimens by referring the ASTM E8 and was eventually undergoing a tensile test to evaluate the mechanical properties. A linear elastic analysis of three different crack characteristics which are single edge crack, double edge crack and center crack were performed in Mode I analysis to evaluate its fracture toughness. The stress intensity factor (SIF) value near the crack tip obtained from the simulation process were then compared with analytical value and had been discussed. The percentage of error found that the numerical and analytical values are closed to each other.
      1  21
  • Publication
    Experimental and finite element analysis on ratchetting behaviour of glass fibre reinforced epoxy composites under cyclic loading
    This study aims to examine the uniaxial and biaxial ratchetting responses of glass fibre reinforced epoxy (GRE) composite by experiment and finite element (FE) analysis. The uniaxial ratchetting of GRE composite laminate was tested under cyclic axial stress with a constant mean stress of 40 MPa and an amplitude stress between 26.67 MPa and 53.33 MPa. The biaxial ratchetting test was also performed on 50 mm diameter of GRE composite straight pipe. The GRE pipe was subjected to a constant internal pressure of 1.875 MPa and 1% of cyclic axial strain. The FE models were simulated using Abaqus in similar loading cases. The uniaxial ratchetting strain was found to increase with the number of cycles, but the ratchetting strain rate was decreased. The specimen showed no further ratchetting and exhibited shakedown after some strain accumulation. On the basis of the experiment and simulation in the biaxial test, it appears that ratchetting would occur in the hoop direction for a GRE pipe with no ratchetting observed in the axial direction. The results showed that the FE analysis over-predicts the ratchetting rate for uniaxial ratchetting test as compared to the experimental values, but under-predicts in the biaxial ratchetting test at initial cycles.
      1  19
  • Publication
    A review of factors influencing peri-implant bone loss
    Dental implants report high survival rate for the treatment of patients with missing teeth and being one of the undeniable restoration techniques. However, peri-implant bone loss has recently arisen to be the highlight in contemporary implant therapy. Therefore, the possible causes that are detrimental to dental implants and surrounding tissues are important to be discovered. The present review focuses on the current etiologies of peri-implant bone loss and subsequent complications observed in clinical practices. A comprehensive literature search was conducted via PubMed, Scopus, and ScienceDirect databases using the related keywords. The literature reveals numerous etiological factors may initiate the loss of marginal bone in dental implant application: loading protocols, implant body placement, implant macro-design features, implant surface roughness, implantation site preparation, foreign body reaction, implant material particles detachment and contamination, and oral habit. Albeit the biomechanical, biological, or combination of factors are known to contribute in marginal bone resorption, the predictability of treatment modalities to handle the defect remains controversial and unclear. Further clinical trials and sophisticated quantitative assessment would be advantageous to help scrutinize the issue.
      19  1